It is known in the art relating to railway locomotives that operation at advanced throttle in long tunnels with multiple locomotive units often results in substantially increased ambient temperatures that cause the engines to lose power and operate with degraded combustion and resulting heavy smoke. To offset the power loss and maintain operator set engine speeds, the traditional speed governor control increases the fuel rate by advancing the governor or injector fuel racks. Sometimes, this further increases the smoke level without any significant increase in the engine power level. The increased ambient temperatures also reduce the cooling effect of the engine cooling system in the locomotive units which may result in engine overheating requiring engine shutdown.